class SingleTone {
  constructor(name, age) {
    this.name = name;
    this.age = age;
    this.instance = null;
  }
}

SingleTone.getName = function () {
  return this.name;
};

SingleTone.prototype.getSingleInstance = function () {
  if (this.instance) {
    this.instance = new singleTone();
  }
  return this.instance;
};
